hs-test: fix LDPreloadIperfVppTest

- fixed ldpreload path (debug build)

Type: test

Change-Id: Ib2ab58b32ffd87a78189464b599f7bbc4f05c175
Signed-off-by: Adrian Villin <avillin@cisco.com>
diff --git a/extras/hs-test/Makefile b/extras/hs-test/Makefile
index c51f70b..596acb1 100644
--- a/extras/hs-test/Makefile
+++ b/extras/hs-test/Makefile
@@ -126,7 +126,7 @@
 	@# necessary so gmake won't skip executing the bash script
 	@-bash ./hs_test.sh --persist=$(PERSIST) --verbose=$(VERBOSE) \
 		--unconfigure=$(UNCONFIGURE) --debug=$(DEBUG) --test=$(TEST) --cpus=$(CPUS) \
-		--vppsrc=$(VPPSRC) --parallel=$(PARALLEL) --repeat=$(REPEAT)
+		--vppsrc=$(VPPSRC) --parallel=$(PARALLEL) --repeat=$(REPEAT) --debug_build=true
 	@bash ./script/compress.sh
 
 .PHONY: test-cov